The present invention relates to a stapling apparatus for stapling multi-sheet printed products of the type having a stamp movably mounted on a shaft, a matrix which bends an essentially straight wire section, and a ram for ejecting the staple.
A stapling apparatus of this type is known, for example, from GB Patent Specification 640,073. The stapling apparatus disclosed in this reference has a cube-shaped matrix, whose front side is beveled. Sunk into the matrix from the front side is a slot extending in an approximately horizontal direction, into which a section of a wire drawn from a roll can be inserted from the side. A stamp cooperating with the matrix is swivelably mounted via a lever to a shaft which extends horizontally. The stamp has two lateral bending sides, which, when the stamp swivels from an upper rest position into a lower staple placing position, bends over downwards the two arms which project laterally over the matrix, of the wire section which has been severed from the wire by means of a cutting blade fastened to the stamp. By means of a ram slidably mounted on the stamp, the staple thus formed, which is guided with the downwardly bent lateral arms in grooves in the bending sides, is pushed out of the stamp and through the printed sheets to be stapled. In the process, the ram slides along the beveled front side of the matrix, and pushes the latter to release the staple, caught in the slot, from the region of the grooves. This known stapling apparatus is conceived as a unit that is operated by hand and independent of other processing stations. This stapling apparatus has the disadvantage that it cannot be matched to different conditions, something which is also prevented by the feeding and severing of the wire, which takes place in a very small space, and the forming and ejection of the staples.
Further stapling apparatuses, which operate in a very similar way, are disclosed in the DE Patent Specifications 955,225 and 38,215 and in the EP-OS 0,013,165 and corresponding U.S. Pat. No. 4,335,841. In these apparatuses, the wire is fed to the matrix or to a holding part arranged on the matrix, and then a wire section is severed. The severed wire section is bent to form a staple by means of a swivelably or slidably mounted stamp which includes lateral bending sides that run past the matrix. The staple is then pushed from the matrix by means of a ram and inserted into the printed sheets.
A further stapling apparatus is known from CH Patent Specification 549,443. A stamp and a ram are slidably guided on a supporting part of a stapling head of this stapling apparatus. To place a staple, the stapling head is moved with the print products that are to be stapled and are deposited onto a collector chain. Subsequently the stapling head is brought back once again, against the conveying direction of the collector chain, into the original position. During this to and from movement, the stapling head runs along a stationary rest plate with two cam paths. One cam path slides the stamp from a rest position which is spaced from the collector chain into the staple placing position, and back again. The other cam path actuates the ram to eject the staple from the stamp, which is located per se in the staple placing position, and simultaneously to place the staple in the print products. Furthermore, a matrix is swivelably mounted on the supporting part in such a way that when the ram is lowered the matrix is swiveled by the ram from the region of a cutout in the stamp and from the region of the ram. A lever which is pretensioned against the matrix is swivelably mounted on the matrix. By means of a wire conveyor, which is likewise mounted on the supporting part and actuated by the ram, the advancing section of a wire is pushed in between the matrix and the lever in a direction perpendicular to the sliding direction of the stamp and of the ram. When the stamp is lowered from the rest position into the staple packing position, the first step is for the stamp to actuate a cutting arrangement that separates the wire section held by the lever and the matrix from the rest of the wire. Subsequently the wire section is bent around the matrix to form a staple. During subsequent lowering of the ram, an eyelet is first bent on the staple. During further lowering of the ram, in conjunction with simultaneous swiveling of the matrix out from the region of the ram and releasing of the lever from the wire section, the staple is ejected from the stamp and forced through the print products. Benders, which bend over the ends of the staple that are pushed through the print products, are provided on the collector chain. In this known stapling apparatus, the cutting to length of the wire, the forming of the staple from the severed wire section, and the placing of the staple take place in a very small space. This leads to a very compact, but also very complicated construction o the stapling head.
Further stapling apparatuses based on the same principle are known from Swiss Patent Specifications 519,933, 586,595 and 662,987.
Furthermore, rotary stapling apparatuses, in which the stapling head is arranged eccentrically on a rotating support disk in each case, are known from U.S. Pat. No. 2,717,383 or the corresponding DE-AS 1,055,499 and U.S. Pat. No. 3,762,622. In the course of a rotation, the stapling head runs past a wire section dispenser, from which the stamp, projecting approximately in the radial direction accepts a wire section. In the course of the further rotation, the grasped wire section is moved along a fixed matrix which is shaped like a slotted link. The matrix bends the wire section to form a staple. As soon as the stapling head reaches the print products, which are conveyed at approximately the rate of rotation of the stapling head tangential to the rotation track of the stapling head, the staple is forced out of the stamp and through the print products by means of a ram. The free ends of the staple are bent by means of a bending head, which likewise rotates. While the staple is being placed, the stapling head experiences small correcting swiveling movements in order to match the stamp to the rate and the direction of movement of the print products.
Therefore, it is an object of the present invention to create a stapling apparatus according to the generic type described above with a simple design, which can be universally employed.